The Physics of Power: How Angular Momentum Shapes the Tennis Forehand

[jeffreycounts]

Ha! Nice!

[airforce1]

Hi Jim,

thanks for the link to this. I might have overlooked it otherwise. I'm confused by this phrase: "wrist extended, which points the strings to the side fence". Given where it appears in the sentence, before mentioning the left hand staying on for the coil, it seems to suggest that they have their wrists extended long before the flip. I thought that the wrist only extends when the inertia of the racket creates the flip in the forward swing? That seems very clear on the gif of Alcaraz hitting a forehand on grass in the article.

Have I misunderstood something? Hugh Clarke, can you clarify??

regards
Rob

When you mention the Flip, do you mean getting into the slot with Lag?

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[dimbleby69]

When you mention the Flip, do you mean getting into the slot with Lag?

th-825753613.jpg

Yes, extension happens as part of the lag, as far as I understand it. The 'flip' triggers the stretch-shorten cycle and rotates the shoulder externally. What Brian Gordon calls the dynamic slot. Hugh Clarke's quote implies that the wrist is already extended before the lag, with the strings parallel to the side fence at the end of the front shoulder stretch.

[airforce1]

In the wooden racket days, no one could conceive that anyone would have so much angular motion that players would some day spin off their front or rear foot and even leave the ground. Perhaps we might all someday witness a 360 degree followthrough!

I can see why many think this, but if you read the book by John Carpenter discussing the history of Stroke Instruction, it shows how all of this was common before 1900 and written about in many books and publication. It appears that the big shift came when Bill Tilden introduced his take on instruction. Swing types didn't seem to have much to do with the racket tec really although poly seems to have ushered in more amplitude overall.
OIP-3681874137.jpg

[airforce1]

Yes, extension happens as part of the lag, as far as I understand it. The 'flip' triggers the stretch-shorten cycle and rotates the shoulder externally. What Brian Gordon calls the dynamic slot. Hugh Clarke's quote implies that the wrist is already extended before the lag, with the strings parallel to the side fence at the end of the front shoulder stretch.

Yes, but I'm not sure why people would claim that other than the SSC becoming such a buzz phrase.
By definition, "The stretch-shortening cycle (SSC) is a muscle action where a muscle is rapidly stretched (eccentric contraction) followed by *an immediate shortening* (concentric contraction).
With a good tennis swing, the racket will continue to Lag (not immediately contract as required for SSC) as it travels up the slot before beginning a controlled release (more or less depending on Fade or Draw) towards neutral position. Brian spoke at length about how the wrist action was not dynamic shortening as many suggest.
Either way, Imo the swivel into the "Slot Entry" is much more efficient and effective than flipping into the slot (or dynamic slot according to Gordon) with the associated problems that it attempted to mitigate from it's ancestor, the Big C.
I prefer "Slot Entry" to dynamic slot as it is more descriptive of what is happening. Dynamic slot seems to suggest that the entry is the whole slot, but that the "Slot" path initially followed up towards the contact is the optimized path. Then he goes on to demo a path that is not very optimized because out of Slot Entry he swoops the path further down before swooping up towards contact (Which is one of the problems with using the Flip). The best Fhs tend to accomplish "Slot Entry" with the racket butt pointing a path or slot directly towards contact and then follows that direct path without swooping down, which is indirect.

Edit: It looks like now they have divided SSC into Fast vs Slow SSC, but I think most of us were seeing this from a standpoint of what they call Fast SSC.

[stroke]

Yes, extension happens as part of the lag, as far as I understand it. The 'flip' triggers the stretch-shorten cycle and rotates the shoulder externally. What Brian Gordon calls the dynamic slot. Hugh Clarke's quote implies that the wrist is already extended before the lag, with the strings parallel to the side fence at the end of the front shoulder stretch.

I have read a lot of Hugh's stuff on the forehand. I am fairly certain what he much prefers is the forehand technique that has the wrist extension as part of the set up on the forehand. All ATP forehands go to a "neutral" wrist position before the final move to contact. Players like Fed, Nadal, Alcaraz, Djokovic, etc, all set up with the extended wrist before contact. Players like Musetti, Zverev, Berrenttini, Kyrgios, Khachanov, Tiafoe, all set up with with at the very least a neutral wrist, although most have this some degree of wrist flexion in the set up. Khachanov and Tiafoe are exteme with the flexion/drooping wrist set up. Hugh is not a fan of this. Personally, I have always felt that because all these ATP forehands go to a neutral, relaxed wrist just prior to the move/lag to contact(BG called in the transition point I think), it is not super important which wrist position one is in during the set up/turn. BG did point out that the very best forehands delay this move into the transition point until the very last moment.

[airforce1]

All ATP forehands go to a "neutral" wrist position before the final move to contact. .

Are you saying they go to neutral as they go into contact or the set up phase?

[stroke]

Are you saying they go to neutral as they go into contact or the set up phase?

They go to neutral before the move to contact, as the final phase of the set up, before the forward movement to contact

[glacierguy]

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[jimlosaltos]

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glacier guy, for me, at least, this shows up as strings of black boxes.

Might either export to plain text or share your secret decoder ring

Thanks!

[seano]

Here's a USPTA seminar from BG where he explains the ATP Type 3 forehand and specifically the role of the wrist and the use of centripetal force. Brian starts to discuss the role of the wrist around the 35:30 mark and our beloved friend John Yandell (RIP), asks a question about the role of the wrist around the 43:00 minute mark.

https://www.youtube.com/watch?v=o2Cqwa5bxV0

[airforce1]

They go to neutral before the move to contact, as the final phase of the set up, before the forward movement to contact

so you mean in the transition from backswing to forward swing?

[airforce1]

It’s All About The Player
But when it comes to efficiency, there are optimal ways to strike the ball, and a straight arm is slightly more optimal and efficient.

Then why are the biggest Fhs on record coming from Bent arm Fhs?

[stotty]

It’s not about having the ‘biggest’ it's about ‘efficiency’. It’s about a player adopting a functional backswing versus a positional backswing. The two best forehands ever thus far are Rafa’s and Roger’s – both positional. A functional backswing is going to involve more work to produce the same thing.

[seano]

Stotty -

I agree with your analysis about forehand efficiency. In addition, bent arm forehands require more effort because you need to bring momentum from the backswing into the forward swing to make up for coming from a closer set up position in the backswing. Positional backswings don't require any momentum from the backswing. Secondly, the use of the forearm is required for spin in a bent arm forehand There's not a direct line from the shoulder to the hand, like there is in a straight arm forehand, where the spin is created from the internal rotation of the shoulder (ISR). The bent arm requires ISR plus the use of the forearm to create the spin.